Assessment of the atomic mobility for the fcc phase of Ni–Co–X (X=Re and Ru) system

The thermodynamic parameters of Co–Re and Co–Ru systems were assessed using the CALPHAD technique. Based on various experimentally measured diffusivities and the thermodynamic parameters, the atomic mobility for the fcc phase of Ni–Co–X (X=Re, Ru) system was assessed using the DICTRA software. Comprehensive comparisons between calculated and experimental diffusion coefficients showed that the experimental data could be well reproduced by the atomic mobilities obtained in the present work. The developed diffusion mobilities were further validated by the prediction of some diffusion behavior, especially the concentration profiles and diffusion paths in diffusion couples.